Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #20 on: July 29, 2004, 12:21:44 PM »
I'm not sure but the filter on Sontec looks like what they call Twin-T filter, but I can be deadly wrong here...
cheers!
Fabio
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TomWaterman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #21 on: July 30, 2004, 03:47:12 PM »
I remember reading that George Massenburg was experimenting with T-filters when he stumbled across the parametric eq!.......

Tom

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #22 on: August 04, 2004, 11:15:04 AM »
I am finally back at this unit. Just took it apart and began to test the filter boards. Just started on channel 2 and all filter boards pass audio when they are connected to the amp board only one each time. Right now i am in the process of testing them together. So far i connected filter boards c-e and all run. On filter board E i get quite some oscillation when setting the frequency pot to the highest frequency and then crank the level pot.
I will look into that later, right now i want to test all filter boards if they pass audio.

Channel 1 is still dead but i will look into this after channel 2 is working. It just seems like channel 1 has more problems so i try to fix the channel with less problems to have one running channel to compare.

Flo

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #23 on: August 04, 2004, 11:43:46 AM »
Ok finished testing for today. Seems like Filter board A on channel 2 is the culprit. I connected filter boards b-e and everything was ok. When i connected filter board A it immediately started to distort. So i will disassemble the filter board and try to find the mistake.
But it's good that there now is some progress with this project.  :grin:

Flo

Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #24 on: August 04, 2004, 11:47:01 AM »
:thumb:  :thumb:  :thumb:

Someone is finishig this!

Don't forget to post pics !!!  :grin:
cheers!
Fabio
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The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #25 on: August 04, 2004, 12:28:01 PM »
Yeah it's warm here too so my motivation to test isn't actually that great (plus i really need to practice guitar more but the heat isn't a good thing while practicing).

I only listened to the oscillation. I just tested if the unit passes audio and heard it while turning the pots. It was quite hearable  :green:

Flo

Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #26 on: August 04, 2004, 12:34:40 PM »
So if you live in here will never do any DIY.... :)

Flo, the channels that are working are stuffed with Melcors??  :razz:

Come on lazy boys!  :grin:
 :sam:
Fabio
cheers!
Fabio
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mik

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #27 on: August 07, 2004, 08:55:08 AM »
hi folks, do ya think is possible to use the neumann boosting amplifer V472
like a amp section for the sontec filter section ?
wat do ya think?
http://www.gyraf.dk/schematics/Neu_472.gif

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #28 on: August 08, 2004, 04:19:51 AM »
Fabio all my channels are stuffed with Melcors.

My second channel now passes audio. But it's quite a bit distorted and i also got some hiss.
Channel 1 still got some problems. Sometimes my "+" voltage drops from +18V to -0,9V and after some time a resistor from the melcor on the filter board d starts to make some smoke signals.  :shock: At the beginning it passes audio very distorted (with no filter board hooked up) but stops working after a while. After that the resistor starts the smoke (the filter boards are all hooked up to the voltage supply).

Man this really will be some work  :shock:

Anybody got any tips about how to best tune the bias settings on the filter boards ?

Flo

Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #29 on: August 20, 2004, 08:41:10 AM »
Flo,

A good pratice, when powering up stuff, is:

1) Left the amps out
2) Turn it up
3) Measure the DC voltages on the opamps pins (on the sockets). Here check if you got the right +V -V Ground must be ok.

gotta go!!! I´ll think about more thinks later
cheers!
Fabio
cheers!
Fabio
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22busy

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #30 on: August 20, 2004, 03:03:04 PM »
I sure hope somebody gets one up and going soon.  :grin:  'Can't wait to get reports on how they sound.  I'd really like to try this project if I could just free up some time.

Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #31 on: August 31, 2004, 08:25:10 AM »
Great Jaakko! pics pics pics pls!

Looks like some local guy has completed his unit, but he doesn´t have a digicam... :roll: .

Fabio
cheers!
Fabio
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TomWaterman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #32 on: August 31, 2004, 10:11:10 AM »
Awesome Jaakko!!

I can´t wait to see this  - all those 992s man its going to look sick!

Just curious Fabio - but once someone gets this running and the project validated, will you be doing another run of boards for this (still got some left??)...I´ve got some cash now and would be very interested.

Cheers Tom

TomWaterman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #33 on: September 14, 2004, 12:08:47 PM »
WOW!! Jaakko! Looking great..... :cool:

Neat idea with the mounting modules - am I right that just the force of the switches screwed to the front will hold the modules in place?

You have implemented Rogys peak/shelf idea and your cut/boost switch - have you got these working on the bench with audio going through the filter cards yet?

Cheers Tom

rafafredd

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #34 on: September 14, 2004, 12:23:46 PM »
Awesome!

Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #35 on: September 14, 2004, 12:48:41 PM »
:grin:  :grin:  :grin:

I'm speechless Jaakko... beautiful job there!!!
I love the solution on the rack case, very nice!!!!!

TURN IT ON PLS!!!!

 :sam:  :sam:  :sam:
cheers!
Fabio
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The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #36 on: September 14, 2004, 02:04:12 PM »
I have quite the boner right now!  

Very nice work.   :guinness:  :sam:  :guinness:  :sam:  :thumb:

TomWaterman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #37 on: September 15, 2004, 05:20:20 PM »
Ha!

WoMP?????

Get busy.....  :razz:  :cool:

Use the force Jedi

Tom

hodad

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #38 on: September 15, 2004, 07:17:50 PM »
If anyone else wants to try out a metal bracket mounting system, you might check out this:
http://www.wiseguysynth.com/larry/bracket.htm

These are designed for use with synth modules & you're pretty much stuck with the hole spacing, but it's a good product at a good price from a good guy.  

Just FYI

Tom

Bauman

The Sontec thread! <ATT. BUILDERS - C22 & C23>
« Reply #39 on: September 17, 2004, 09:28:18 AM »
:grin:  :grin:  :razz:  :razz:  :cool:  :cool:
cheers!
Fabio
_____________________
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